The overall project is divided into 7 subprojects, each the responsibility of a project leader or in cooperation with several investigators. In the cholinesterase purification project, kinetic and physical evidence for existence of multiple molecular forms of ChE will be investigated. The project on a molecular basis for selective toxicity will primarily be directed to purification and separation of glutathione transferases and work on separation of the optical isomers of EPN will be initiated. Herbicide action and metabolism studies will primarily involve identification of specific sites of herbicide action with isolated mitochondria and chloroplasts through use of electron microscopy. Microsomal oxidation studies will involve solubilization and purification of cytochrome P-450 in several mouse and insect strains differing quantitatively and qualitatively. In genetic studies, IPS- and CIPC-type herbicides will be included in standard studies with wasps and brine shrimp. In subcellular localization, work with insecticide binding in blood of mammals and insects will be extended to several groups of insecticides and further work will be made on a method to evaluate reentry into pesticide-treated fields by use of laboratory animals.